Process of burning cement and apparatus therefor.



PATENTED MAR. 12, 190 7. H. L. DOHERTY. PROCESS OF BURNING CEMENT AND APPARATUS THEREFOR.

APPLICATION FILED APR.7, 1906.

l/VVENZOR W aim ZS BY ATTORNEY WITNESSES:

W AM

1 r produced To all) whom it may concern UNITED STATES PATENT omen.

HENRY L. DonER'rY, 0E MADISON, WISCONSIN. PROCESS oF suanme CEMENT ANDVAPPIARATIUSV THEREJIFOIR.

Be it known that I, HENRY L. Domm'rr, acitizen of the United States, and a resident'of Madison, in the county of Dane and State of Wisconsin, have invented certain new and useful Processes of .Burn' Apparatus Therefor, of whic the following J is a specification.

The present process relates to burning cement-clinker m inclined rotary kilns by means of a tempered impinging-flame of powdered fuel. i

In the practice of the art of cement-burn ing ithas heretofore been customary to perform the operation of clinkering with a flame y the burning of powdered fuel with ordinary air. With such aflame it has been foundnecessary .to take extremeprecaution to prevent the flame from striking or impinging upon either the material or-fthe" walls of the kiln. Such methods are noteconomical, for the reason that the, removal' .of the flame to a point distant from the p'lace of utilization of the heat makes it necessaryto rely on radiation alone for the transference of'heat to the material. Y I

The present invention has for its object the production of a flame which can be brought in contact or in proxlmityto the material or'even the walls of the without any deleterious effects.

v [H A further object is the iutroduetioninto the flame of a catalytic body'na'mely, steam or water-vapor'gfor the purposeof assisting in the formatio of clinker.

It has been previously proposed to make useofsteam or watervapor in the'burning suggested so far as I am advised, inconnection with the use of anaxialflame or of a.

flame which is substantially parallel to the axis of the kiln. Under such circumstances contact withthe material and thereby per form useful work. In the o 'eration of clinkering cement a number o .reactions of a complex nature occur, and, in fact, the exact character of all the reactions which go on at this stage is far from clear. Investigations. show that steam or water-vapor has a pecnliar action on silica at the time of transfer- Cement and l of cement ;,but all such proposals have been Patented March 12, 1907.

mation into silicates. and, on the whole, steam appears to have a beneficial action in acceleratlng the combination of silica with lime,

ture of the flameis carefully're dated, is fairly uniform; and is not. excesslvely'high. In burning powdered coal with ordinaryair, containing approximately, twenty-one per cent. of ox gen, a very high flame temperalocali'zed and for that reason' is not adapted to burningcement-clinker uniformly. gation of the effect of suchlocalized combuswhich makes possible the use of an impinging -c amberj2 at its upper en and inclosed by a hood 3.at the lower end. A stack-4 is pro vided for the" removal of the roducts of combustion. Connected with t e hood by meansof the singlepipe 5- is a coal-fee blower L r .8 is a clinker-pit into which the hot clinker from thekiln 1 .fallsg? In this clinker-pit is which water-is supplied. The outlet 11 of said coil terminates 1n' the. blast-pipe 5. The

of the kiln in the jusju:al manner an downwardly along theibarrel of the kiln rotatin the latter. .the igmted blast of coal and ainflentering through the pi e'Sis sp directed that the ma terial1s bathe aluminium, and iron, provided the tempera-- tion and excessively-high temperatures is part secured by the use of a non-impinging flame. 'B my invention, however, uniform. and lesse ocalized combustion is attained,..', f

. 7 flame and .permits of the effectiveuse of a arrel enteri a ousingordustr,

mechanism 6, towhich air is supplied by the l ture is reac ed." The heat, however, is much Mitiplaced a coil of pipe 9, to the inletll). of

raw. material is entered into the upper part passed.

7 dpon' The flame produce by IOO V in burning and incandescent gases. Water isentered throughiq into the coil 9 and is converted intovapor or'steam' by the heat of the dischargedclinker, which steam. to be used. A'hig collects in 81 Steam thus ge erated dis charges into the ipe 5 and mixes with the coal and ,air. 1T e amount of Steam-introduced ,is' regulated y a suitable cock. The

" 9? 9 h s e m ism l we th fl t perature, and the amount introduced is obusl dependent uponthe flame temperature' es1red. One to three per cent, is 'us'u ally sufficient in the b j of Por la merit made from silicate rot Th amount 7 II of sulfur in ithe'fuelshou'ld be taken into con,-

sideration determining the quantity of in coal usually calls for ,a sh htly larger: quantity'of steam 'over that .a ove mentioned. The steam required may be generated in ther ways.as, for instance, by ,means'of a Q m bOiIer pIaced in the stack ,4, The quantity of steam may be varied intermittently or periodically,'.1f desired, and in case of the formation] ofincrustations of clinker on vthe walls ofthe it, is-desira-ble for'a short time to considerably increase this proportion of steam or to suddenly and freguentjlyyary the .quantity'until'the rin 1s dislodged. In burning cement with 0rd? naryian' no means are at hand for the efiiclent removal 'ofrin'gs, and it is necessary un der former racticeto' stop the kiln and re- ,move the mcrustations by manual ieflort. My invention aids in the removal of rings, so

that stoppages areless frequent It is. a well-known fact that water-vapor exerts a beneficial action in the calcination of limestone. The -raw" for ordinary Portland cement contains about thirty per cent. .of carbon dioxid. The'presence of the additional amount of steam other than'that,

coming from the fuel resultsin an im' roved calcination of thelim'estone. The mic is more easily from the carbon dioxid with which it is combined-in an atmosphere containinga substantial amount. of watervor., I

I do not limit myself in the production of an impinging and catalyzing flame in this manner solely to the use ofsteam, as I may under certain circumstances use products of combustion in conjunction with steam for thispurpose', v-

- I am aware that the use of the stack-gases for the regulation of flame temperature is not new, and I do not la claim to the use of air and product'sofcom u'stion withoutv the addition of steam.

I The process of busing Element-shaker 1n rotary kilns which consists direct y im' pinging on an advancing stream of, cement material in such a tempered flame of burnin fuel carried by a jet of commin'gled air an steam, the relative proportion of content of sulfur pinging on an advancing .stream of cement material in such kilns, a tempered flame I of burning-fuel carried by an aeriform jet containing a modicum of steam, the proportion .of steam in sii'ch jet being regulated ,to con} fine the temperature produced within the upper and lower limits of safe clinkerin temperatures, and from time to time slightly modifying-said proportion within said limits to obviate ring formation.

4. The process of but which consists in impinging'on an advancing thelproportion of steam in such jet being ated to confinethe'temperature pro- 3. Th recess of burningcement-clinker I in rotary us which consists in directly im- 'ng cement-clinker stream of cement'materialsa tempered flame of powdered coalo'arried by an air-jet con taming sufficient water-vapor to temper and confine the temperature reduced within the upper and lower limits 0 safe clinkering temperatures. I

5., The recess of burning cement-clinker in rotary "l dlns which-consists in directly imI- pinging on an advancing stream of cement materials in such kilns a tempered flame of owdered coal carried by an air-jet 'containmg sufficient waterevapor to temper and confine the temperatnrefproduced within the upper and lower limits o roportion within such to obviate ring ormation. v o a 6. A cement-clinker apparatus comprising a rotary inclined kiln, means for feeding raw material thereto and removing finished clinker therefrom, and flame-producing means there-t for comprising aburner arranged to direct a flame into (lirectfimping'em'ent upon material .aelvanfcing therethr'ough, a feeding do: vice furnishing said burner with powdered fuel, air-supplying means for transporting said fuel to and through the burner: into imingement upon the material and means for .urnishing to said air a modicum of steam.

7. A cement-clinker apparatus vcomprising a rotary inclined kiln, means for feeding raw I I safe clinkering tem- .peratures,. and in periodical'ly' .varying such IIO material theretoandremovingfinishdcl nker therefrom, and flame-producing meanstherefor comprising a burner arranged to direct a flame into direct impingement upon material advancing the'rethrough, a feed device furnishing said burner with powdered fuel, I Signed at New York, in the county of New air-supplying means for transporting said a fuel to and through the burner, and awater- March, A. D. 1906.

vaporizing device located in proximity to the clinker-removing means and having a pipe connection with said flame-producing means Witnesses: whereby undue heat of the impinging flame i FLETCHER P. SCOFIELD, may be tempered. i FRED. I. SMITH.

HENRY L; 'DOI-IERTY.

York andState of New York, this 16th day of to 

